From 840c7eb25814a804734794a2872c3c94b233a8ae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Tue, 19 Sep 2017 19:30:24 +0200
Subject: [PATCH] checkFloatToIntegerOverflow: check all calculations, not only
 in function bodies

---
 lib/checktype.cpp | 97 ++++++++++++++++++++++-------------------------
 test/testtype.cpp |  7 +++-
 2 files changed, 51 insertions(+), 53 deletions(-)

diff --git a/lib/checktype.cpp b/lib/checktype.cpp
index e34e3e0fc..66f8b6ae3 100644
--- a/lib/checktype.cpp
+++ b/lib/checktype.cpp
@@ -344,65 +344,60 @@ void CheckType::longCastReturnError(const Token *tok)
 
 void CheckType::checkFloatToIntegerOverflow()
 {
-    const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
-    const std::size_t functions = symbolDatabase->functionScopes.size();
-    for (std::size_t i = 0; i < functions; ++i) {
-        const Scope * scope = symbolDatabase->functionScopes[i];
-        for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
-            const ValueType *vtint, *vtfloat;
-            const std::list<ValueFlow::Value> *floatValues;
+    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
+        const ValueType *vtint, *vtfloat;
+        const std::list<ValueFlow::Value> *floatValues;
 
-            // Explicit cast
-            if (Token::Match(tok, "( %name%") && tok->astOperand1() && !tok->astOperand2()) {
-                vtint = tok->valueType();
-                vtfloat = tok->astOperand1()->valueType();
-                floatValues = &tok->astOperand1()->values();
-            }
+        // Explicit cast
+        if (Token::Match(tok, "( %name%") && tok->astOperand1() && !tok->astOperand2()) {
+            vtint = tok->valueType();
+            vtfloat = tok->astOperand1()->valueType();
+            floatValues = &tok->astOperand1()->values();
+        }
 
-            // Assignment
-            else if (tok->str() == "=" && tok->astOperand1() && tok->astOperand2()) {
-                vtint = tok->astOperand1()->valueType();
-                vtfloat = tok->astOperand2()->valueType();
-                floatValues = &tok->astOperand2()->values();
-            }
+        // Assignment
+        else if (tok->str() == "=" && tok->astOperand1() && tok->astOperand2()) {
+            vtint = tok->astOperand1()->valueType();
+            vtfloat = tok->astOperand2()->valueType();
+            floatValues = &tok->astOperand2()->values();
+        }
 
-            // TODO: function call
+        // TODO: function call
 
-            else
+        else
+            continue;
+
+        // Conversion of float to integer?
+        if (!vtint || !vtint->isIntegral())
+            continue;
+        if (!vtfloat || !vtfloat->isFloat())
+            continue;
+
+        for (std::list<ValueFlow::Value>::const_iterator it = floatValues->begin(); it != floatValues->end(); ++it) {
+            if (it->valueType != ValueFlow::Value::FLOAT)
                 continue;
-
-            // Conversion of float to integer?
-            if (!vtint || !vtint->isIntegral())
+            if (!_settings->isEnabled(&(*it), false))
                 continue;
-            if (!vtfloat || !vtfloat->isFloat())
-                continue;
-
-            for (std::list<ValueFlow::Value>::const_iterator it = floatValues->begin(); it != floatValues->end(); ++it) {
-                if (it->valueType != ValueFlow::Value::FLOAT)
+            if (it->floatValue > ~0ULL)
+                floatToIntegerOverflowError(tok, *it);
+            else if ((-it->floatValue) > (1ULL<<62))
+                floatToIntegerOverflowError(tok, *it);
+            else if (_settings->platformType != Settings::Unspecified) {
+                int bits = 0;
+                if (vtint->type == ValueType::Type::CHAR)
+                    bits = _settings->char_bit;
+                else if (vtint->type == ValueType::Type::SHORT)
+                    bits = _settings->short_bit;
+                else if (vtint->type == ValueType::Type::INT)
+                    bits = _settings->int_bit;
+                else if (vtint->type == ValueType::Type::LONG)
+                    bits = _settings->long_bit;
+                else if (vtint->type == ValueType::Type::LONGLONG)
+                    bits = _settings->long_long_bit;
+                else
                     continue;
-                if (!_settings->isEnabled(&(*it), false))
-                    continue;
-                if (it->floatValue > ~0ULL)
+                if (bits < 64 && it->floatValue >= (1ULL << bits))
                     floatToIntegerOverflowError(tok, *it);
-                else if ((-it->floatValue) > (1ULL<<62))
-                    floatToIntegerOverflowError(tok, *it);
-                else if (_settings->platformType != Settings::Unspecified) {
-                    int bits = 0;
-                    if (vtint->type == ValueType::Type::CHAR)
-                        bits = _settings->char_bit;
-                    else if (vtint->type == ValueType::Type::SHORT)
-                        bits = _settings->short_bit;
-                    else if (vtint->type == ValueType::Type::INT)
-                        bits = _settings->int_bit;
-                    else if (vtint->type == ValueType::Type::LONG)
-                        bits = _settings->long_bit;
-                    else if (vtint->type == ValueType::Type::LONGLONG)
-                        bits = _settings->long_long_bit;
-                    else
-                        continue;
-                    if (bits < 64 && it->floatValue >= (1ULL << bits))
-                        floatToIntegerOverflowError(tok, *it);
-                }
             }
         }
     }
diff --git a/test/testtype.cpp b/test/testtype.cpp
index ca300a60e..88b62b88a 100644
--- a/test/testtype.cpp
+++ b/test/testtype.cpp
@@ -148,9 +148,9 @@ private:
     }
 
     void signConversion() {
-		check("x = -4 * (unsigned)y;");
+        check("x = -4 * (unsigned)y;");
         ASSERT_EQUALS("[test.cpp:1]: (warning) Suspicious code: sign conversion of -4 in calculation because '-4' has a negative value\n", errout.str());
-		
+
         check("unsigned int f1(signed int x, unsigned int y) {" // x is signed
               "  return x * y;\n"
               "}\n"
@@ -235,6 +235,9 @@ private:
     }
 
     void checkFloatToIntegerOverflow() {
+        check("x = (int)1E100;");
+        ASSERT_EQUALS("[test.cpp:1]: (error) Undefined behaviour: float () to integer conversion overflow.\n", removeFloat(errout.str()));
+
         check("void f(void) {\n"
               "  return (int)1E100;\n"
               "}\n");